1082-19-5Relevant academic research and scientific papers
Monitoring helical twists and effective molarities in dinuclear triple-stranded lanthanide helicates
Ryan, Patrick E.,Guenee, Laure,Piguet, Claude
, p. 11047 - 11055 (2013)
The replacement of terminal benzimidazole-pyridine binding units in the neutral di-tridentate segmental ligand L1 with phenanthroline in L10 reduces the number of torsional degrees of freedom by two units. Reactions of these ligands with trivalent europium or lutetium cations yield structurally similar self-assembled dinuclear triple-stranded [Ln2(Lk)3] 6+ complexes, thus demonstrating that the increased rigidity of the strand in L10 is compatible with its helical twist. With the larger lanthanum cations, the metallic coordination spheres are completed with two terminal axial triflate counter-anions to give [La2(L10)3(CF 3SO3)2]4+. Thermodynamic investigations in acetonitrile confirm the minor constraints produced by the planar phenanthroline unit in L10 leading to comparable effective molarities EMEu,L1 ≈ EMEu,L10 = 10 -3.9(4) M with mid-range EuIII cations. The striking minute effective molarities EMLn,Ln-2H ≈ 10-6-10-9 M obtained upon the replacement of terminal phenanthrolines with structurally analogous fused hydroxyquinolines in L9 can be thus unambiguously assigned to solvation effects, a new tool for controlling complexity in metal-induced self-assembly processes.
A single iron porphyrin shows ph dependent switch between "push" and "pull" effects in electrochemical oxygen reduction
Bhunia, Sarmistha,Dey, Abhishek,Dey, Somdatta Ghosh,Mukherjee, Sudipta,Nayek, Abhijit
, p. 14564 - 14576 (2020)
The "push-pull"effects associated with heme enzymes manifest themselves through highly evolved distal amino acid environments and axial ligands to the heme. These conserved residues enhance their reactivities by orders of magnitude relative to small molecules that mimic the primary coordination. An instance of a mononuclear iron porphyrin with covalently attached pendent phenanthroline groups is reported which exhibit reactivity indicating a pH dependent "push"to "pull"transition in the same molecule. The pendant phenanthroline residues provide proton transfer pathways into the iron site, ensuring selective 4e-/4H+ reduction of O2 to water. The protonation of these residues at lower pH mimics the pull effect of peroxidases, and a coordination of an axial hydroxide ligand at high pH emulates the push effect of P450 monooxygenases. Both effects enhance the rate of O2 reduction by orders of magnitude over its value at neutral pH while maintaining exclusive selectivity for 4e-/4H+ oxygen reduction reaction.
Substituted phenanthrolines as antennae in luminescent EuIII complexes
Akerboom, Sebastiaan,Van Den Elshout, Jos J. M. H.,Mutikainen, Ilpo,Siegler, Maxime A.,Fu, Wen Tian,Bouwman, Elisabeth
, p. 6137 - 6146 (2013)
Eight novel europium(III)-based coordination compounds with 1,10-phenanthroline (phen) ligands with a chloro, methoxy, ethoxy, cyano, carboxylic acid, methyl carboxylate, ethyl carboxylate, and amino substituent on the 2-position have been prepared in yields ranging from 43 to 89 %. Additionally, one lanthanum(III) coordination compound of 2-amino-1,10- phenanthroline has been isolated. All compounds have the general formula [Ln(L)2(NO3)3], except for the compound with the carboxylate ligand, which has the formula [Eu(O2Cphen) 3]. Three of the EuIII complexes as well as the La III compound crystal structures have been determined, all of which show similar N4O6 coordination spheres for the Ln III ion. Seven compounds exhibit bright luminescence that is characteristic of EuIII upon irradiation with near-UV radiation, thus indicating efficient ligand-to-metal energy transfer. The complex with 2-amino-1,10-phenanthroline is nonluminescent. The solid-state photoluminescent quantum yields range from 10 to 79 %, and the luminescence lifetimes vary from 0.43 to 1.57 ms. Analysis of the spectral intensities with the Judd-Ofelt theory shows a significant contribution of nonradiative processes that quench the luminescence of the 5D0 level on EuIII. Eight new EuIII complexes with 1,10-phenanthroline ligands substituted on the 2-position have been prepared, analyzed, and the photoluminescence properties studied. The complex with the 2-chloro substituent exhibits bright photoluminescence with a high quantum yield of 78 %. The complex with the 2-amino substituent is nonluminescent. Copyright
Hybrid bis-histidine phenanthroline-based ligands to lessen aβ-bound cu ros production: An illustration of cu(i) significance
Drommi, Marielle,Esmieu, Charlène,Hureau, Christelle,Rulmont, Clément
supporting information, (2021/12/24)
We here report the synthesis of three new hybrid ligands built around the phenanthroline scaffold and encompassing two histidine-like moieties: phenHH, phenHGH and H’phenH’, where H correspond to histidine and H’ to histamine. These ligands were designed to capture Cu(I/II) from the amyloid-β peptide and to prevent the formation of reactive oxygen species produced by amyloid-β bound copper in presence of physiological reductant (e.g., ascorbate) and dioxygen. The amyloid-β peptide is a well-known key player in Alzheimer’s disease, a debilitating and devasting neurological disorder the mankind has to fight against. The Cu-Aβ complex does participate in the oxidative stress observed in the disease, due to the redox ability of the Cu(I/II) ions. The complete characterization of the copper complexes made with phenHH, phenHGH and H’phenH’ is reported, along with the ability of ligands to remove Cu from Aβ, and to prevent the formation of reactive oxygen species catalyzed by Cu and Cu-Aβ, including in presence of zinc, the second metal ions important in the etiology of Alzheimer’s disease. The importance of the reduced state of copper, Cu(I), in the prevention and arrest of ROS is mechanistically described with the help of cyclic voltammetry experiments.
Method for synthesizing 2-acetyl-1, 10-phenanthroline (3)
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Paragraph 0015; 0016; 0017; 0018; 0019, (2019/08/20)
The invention discloses a method for synthesizing 2-acetyl-1, 10-phenanthroline (3). The method comprises the following steps: using 1, 10-phenanthroline as a raw material to synthesize 2-cyano-1, 10-phenanthroline (2) by reacting with trimethylcyanosilane, trifluoromethanesulfonic anhydride, 1, 8-diazabicycloundec-7-ene; and then reacting 2-cyano-1, 10-phenanthroline (2) with methyl lithium to prepare 2-acetyl-1, 10-phenanthroline (3). The method provided by the invention prepares 2-acetyl-1, 10-phenanthroline (3) by adopting a two-step synthesis method, is beneficial to the increase of the yield, and purifies by quenching with a saturated sodium bicarbonate solution, extracting with dichloromethane and washing with a saturated sodium chloride solution after completing a first step, so that the influence of impurities generated in the first step on the reaction in a second step is minimized.
C?H Cyanation of 6-Ring N-Containing Heteroaromatics
Elbert, Bryony L.,Farley, Alistair J. M.,Gorman, Timothy W.,Johnson, Tarn C.,Genicot, Christophe,Lallemand, Bénédicte,Pasau, Patrick,Flasz, Jakub,Castro, José L.,MacCoss, Malcolm,Paton, Robert S.,Schofield, Christopher J.,Smith, Martin D.,Willis, Michael C.,Dixon, Darren J.
supporting information, p. 14733 - 14737 (2017/10/07)
Heteroaromatic nitriles are important compounds in drug discovery, both for their prevalence in the clinic and due to the diverse range of transformations they can undergo. As such, efficient and reliable methods to access them have the potential for far-reaching impact across synthetic chemistry and the biomedical sciences. Herein, we report an approach to heteroaromatic C?H cyanation through triflic anhydride activation, nucleophilic addition of cyanide, followed by elimination of trifluoromethanesulfinate to regenerate the cyanated heteroaromatic ring. This one-pot protocol is simple to perform, is applicable to a broad range of decorated 6-ring N-containing heterocycles, and has been shown to be suitable for late-stage functionalization of complex drug-like architectures.
Tridentate Directing Groups Stabilize 6-Membered Palladacycles in Catalytic Alkene Hydrofunctionalization
O'Duill, Miriam L.,Matsuura, Rei,Wang, Yanyan,Turnbull, Joshua L.,Gurak, John A.,Gao, De-Wei,Lu, Gang,Liu, Peng,Engle, Keary M.
supporting information, p. 15576 - 15579 (2017/11/14)
Removable tridentate directing groups inspired by pincer ligands have been designed to stabilize otherwise kinetically and thermodynamically disfavored 6-membered alkyl palladacycle intermediates. This family of directing groups enables regioselective remote hydrocarbofunctionalization of several synthetically useful alkene-containing substrate classes, including 4-pentenoic acids, allylic alcohols, homoallyl amines, and bis-homoallylamines, under Pd(II) catalysis. In conjunction with previous findings, we demonstrate regiodivergent hydrofunctionalization of 3-butenoic acid derivatives to afford either Markovnikov or anti-Markovnikov addition products depending on directing group choice. Preliminary mechanistic and computational data are presented to support the proposed catalytic cycle.
O-phenanthrene pyrrodiazoles rare earth complex and its preparation method
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Paragraph 0044-0046, (2016/10/08)
The invention provides a novel o-phenanthroline triazole rare earth complex LnL3 and a preparation method thereof. The structural formula of the o-phenanthroline triazole rare earth complex LnL3 is shown in formula 1, wherein R1 is selected from amino, alkyl or aromatic hydrocarbon groups, R2 is selected from amino, alkyl or aromatic hydrocarbon groups, R3 is selected from amino, halogen, alkyl, halogenated alkyl or aromatic hydrocarbon groups, and a central rare earth ion Ln is selected from any one of yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium. The o-phenanthroline triazole rare earth complex LnL3 disclosed by the invention takes an o-phenanthroline triazole trident compound as a single ligand, and satisfies the ligand saturation, and a situation that a charge balance is electrically neutral is realized between triazole groups in the complex as anions and central rare earth metal cations. The rare earth complex disclosed by the invention is high in thermal stability, and is suitable for device preparation implemented by using an evaporation film-forming process or a solution film-forming process. The preparation method is high in yield, good in product purity, short in reaction time and simple in operation, and the cost is greatly reduced.
Nitrogen-containing tooth heterocyclic ring substituted tetrazole rare earth complex and its preparation method
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Paragraph 0109-0111, (2016/11/24)
The invention provides a nitrogen-containing double-tooth heterocyclic ring substituted tetrazole type rare-earth complex LnL3 expressed by the formula I, wherein Ar is a nitrogen-containing double-tooth heterocyclic ring; the center rare-earth ion Ln is any one of yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium. The preparation method of the nitrogen-containing double-tooth heterocyclic ring substituted tetrazole type rare-earth complex LnL3 is characterized in that a nitrogen-containing double-tooth heterocyclic ring substituted tetrazole type three-tooth compound, namely a dipyridyl tetrazole type three-tooth compound or phenanthroline tetrazole type three-tooth compound, is taken as a single ligand, and simultaneously, coordination saturation is satisfied, and the tetrazole group in the complex serves as negative irons to realize electrically neutral charge balance together with center rare-earth metal cations. The obtained rare-earth complex is high in thermal stability, can be prepared into a device through an evaporation film-forming process or a solution film-forming process. Besides, the preparation method has the advantages of high yield, of the product has high purity, reaction time is short and operation is simple; and as a result, the cost is greatly reduced.
Highly effective recognition of carbohydrates by phenanthroline-based receptors: α- versus β-anomer binding preference
Mazik, Monika,Hartmann, Andre,Jones, Peter G.
scheme or table, p. 9147 - 9159 (2010/04/05)
1H NMR spectroscopic titrations in competitive and non-competitive media, as well as binding studies in two-phase systems, such as phase transfer of sugars from aqueous into organic solvents and dissolution of solid carbohydrates in apolar medi
